An MRI of a musician trying to identify a note. We can see how the blood flow increases in specific regions of the auditory cortex during this task. | Image: J. Benner et al. (2023)

People with perfect pitch can identify the pitch of a musical note, apparently without thinking about it and without reference to anything else. This can be especially advantageous to musicians. In the population as a whole, only one in ten thousand people possesses this extraordinary ability. A new study has now shown that people with perfect pitch can process sounds quicker.

Hearing a note triggers an electrical impulse in the auditory cortex of our brain. The study in question showed that this impulse is transmitted quicker among people with perfect pitch – and this happens even more quickly in the right hemisphere of the brain than in the left. The differences involved are in the milliseconds. “We have been able to show that signal-processing already works differently at the early sensory level, not just at the cognitive level where a note is given a name”, says Maria Blatow, a senior physician in neuroradiology at the Lucerne Cantonal Hospital.

In order to achieve a high degree of accuracy when recording both the spatial sequence and the temporal sequence of signal-processing in the auditory cortex, Blatow and her team measured both the blood flow and the magnetic signals involved, then combined their respective results. This is the first time that these two different means of measuring brain activity have been linked. Their study involved 40 musicians, 17 of whom had perfect pitch. They focused on this group because their brains show a heightened reaction to acoustic signals.

The proportion of people possessing perfect pitch is significantly higher among musicians than is the case among the general population. This isn’t just because those with favourable genes are more likely to become musicians. Practice also plays a role. “A genetic predisposition indeed exists. For example, someone might already have a larger auditory cortex at birth”, says Blatow. “But perfect pitch can also be trained, though it’s easier for those who possess this predisposition than for those without it”. Blatow and her fellow researchers are now investigating the role of musical training in a follow-up study that will monitor music students during their education.

J. Benner et al.: Temporal hierarchy of cortical responses reflects core-belt-parabelt organization of auditory cortex in musicians. Cerebral Cortex (2023)